Memory Management Under WOW64

Memory management under WOW64 depends on the processor architecture.

Itanium Support

WOW64 simulates 4 KB pages on top of the native 8 KB pages that the Itanium processor uses. The processor assists
by providing excellent simulation with low overhead. The simulation code cannot handle the following cases:

Write tracking. The GetWriteWatch and
ResetWriteWatch functions are implemented in the
kernel using native page-size granularity, which means the WOW64 4 KB page simulation cannot determine which
simulated 4 KB pages are written within the underlying 8 KB page.

Section alignment. For executable images with section alignment smaller than 8 KB (the default is 4 KB for x86
images), WOW64 must dirty all image pages. This effectively copies each page to the page file, and prevents
read-only image pages from being shared between processes.